The present invention relates to the field of photography and, more particularly, to a camera, usable in a microfiche system, for recording a plurality of images on a single card-like film unit, preferably of the self-developing type.
Commonly-assigned copending application, U.S. Ser. No. 098,492, filed by P. R. Norris on Nov. 29, 1979, discloses a microfiche camera of the type including a plate having a plurality of gate apertures therein for defining a laterally extending row of image areas on a portion of a film unit supported for longitudinal movement along a film plane and an objective lens mounted on a carriage for incremental movement in linear passes along the row during which the lens is successively located in imaging relation with each of the image areas. A barrel cam, advanceable in predetermined rotational increments, incrementally moves the lens in one direction from a starting position to a terminal position during one linear pass and then moves the lens in the opposite direction back to the starting position during the next linear pass. The camera also includes a system, including a shutter, for controlling exposure; structure on the barrel cam for normally operating the shutter each time the barrel cam is advanced through one of its rotational increments; a film advancing system for incrementally advancing the film unit longitudinally after each linear pass to present the next portion of the film unit in registration with the image area defining apertures; and a drive system, including an energizable electrical motor, for rotatably driving the barrel cam. In a preferred embodiment, the camera utilizes a self-developing film unit and includes a pair of processing rollers configured to be driven by the motor for processing the film unit following exposure. Also, the camera includes a self-contained strobe flash unit for illuminating documents to be photographed. The strobe unit is designed to be fired automatically in response to shutter operation.
Normally, the camera is operated in a succession of single frame exposure cycles until all of the image areas on the film unit are exposed. The camera then is actuated one more time which causes the film to be advanced into the rollers for processing. The completion of the processing cycle results in the lens and barrel cam being automatically repositioned at a predetermined starting position in preparation for initiating exposure of the next film unit.
Sometimes, however, it is desirable to process the film unit before all of the image areas thereon have been exposed. Typically, the film unit may include 49 image areas all of which are not required to record a group of related documents. Accordingly, a pick slide member forming part of the film advancing system may be advanced manually after the completion of any exposure cycle to initiate the film processing cycle. When this occurs, it is most likely that the lens and the barrel cam will not be in their proper starting positions to expose the first image area on the next film unit.
Therefore, it is desirable to provide such a camera with a motor control system that not only operates in exposure cycle and processing cycle modes, but additionally operates the camera in a reset cycle mode for resetting the lens and barrel cam back to their respective starting positions. Also, it is preferable that the shutter and strobe unit not operate during such a reset cycle to prevent extraneous light from entering the camera and possibly fogging the next film unit and for reducing wear and tear on the shutter mechanism and strobe unit.
Commonly-assigned copending application, U.S. Ser. No. 072,051, now U.S. Pat. No. 4,235,543 discloses a microfiche camera having a control system which operates in a reset cycle mode. However, this system is mechanically complex in that it uses a motor driven reset pawl to drive a reset ratchet wheel coupled to the barrel cam. This feature is also disclosed in commonly-assigned copending applications Ser. Nos. 071,939; 071,940; and 088,766.
Commonly-assigned copending application U.S. Ser. No. 047,057 discloses a hand viewer for card movies in which a pivoting lens mounting boom is reciprocally driven by an electrical motor for scanning successive rows of images on a film unit. The viewer includes a control system which operates a motor in a reset cycle mode and includes a cam for opening an electrical switch when the boom has returned to the starting position for deenergizing the motor to end the reset cycle. The control system uses a separate cam that is keyed to the rotation of the barrel cam for opening the switch. However, the barrel cam in that application is adapted to be driven on a continuous basis rather than in precise rotational increments required for proper operation of a microfiche camera.
Commonly-assigned copending applications, U.S. Ser. Nos. 047,024 and 047,115, disclose a card motion picture camera having a motor control circuit for operating a first motor for driving the barrel cam and a second motor for driving the film processing rollers. Such a control system utilizes multi-pole switching arrangements and tends to be overly complex and too expensive for use in a microfiche camera.
Therefore, it is an object of the present invention to provide a microfiche camera having a motor control system which is simple in its construction and accurate in its operation.
It is another object of the invention to provide a microfiche camera having a motor control system which utilizes a minimum number of switches and operates in exposure cycle, processing cycle, and reset cycle modes of operation.
Another object of the invention is to provide a microfiche camera having structure for automatically disenabling shutter and strobe operation during a reset cycle and for enabling such operation during an exposure cycle.
Other objects of the invention will, in part, be obvious and will, in part, appear hereinafter.